Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002962 (angina)
 21,142 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To assess the differences in the pathogenesis of cardiac ischemic events and the role of the autonomic nervous system, we studied the electrocardiographic measures of tonic vagal activity during 24-hour Holter monitoring. We tested the circadian rhythm of the power in the high frequency energy (HF: 0.15-0.40 Hz) of the normal R-R interval power spectrum, the daily percent of successive normal R-R greater than 50 ms (pNN50) and the roots mean square of successive difference of normal R-R intervals (MMSD) in patients with coronary artery disease of comparable angiographic severity. Group A consisted of 5 patients (mean age 62 +/- 8) with chronic stable angina and Group B of 5 patients (mean age 61 +/- 8) with variant angina. Characteristic anginal pattern, typical ST changes during ischemic events on Holter monitoring and angiographic evidence of vasoconstriction induced by hyperventilation distinguished the 2 groups. Mean Cosinor analysis showed the presence of a significant circadian rhythm of HF only in Group A with a peak in the early morning hours (phi at 03.45, % rhythm 50.0, p less than 0.03); a significant reduction of parasympathetic activation was also found in Group B (MSSD: 27.8 vs 15.4, p less than 0.05; pNN50: 2.9 vs 0.6, p less than 0.05). These results suggest a different pattern in circadian variation of HF and lower degree of time and frequency domain of heart rate variability, as a marker of vagal tone in patients with high susceptibility to coronary vasospasm.
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PMID:[An analysis of the variability in the heart rate in relation to the presence of transient ischemia and to its physiopathological mechanism]. 158 21

In order to evaluate whether variations in autonomic nervous tone have a significant role in the induction of coronary arterial spasm in variant angina, we analyzed the changes in heart rate variability (HRV) related to spontaneous episodes of ST-segment elevation, recorded during 24-hour ambulatory ECG monitoring, in 13 patients with variant angina (9 men and 4 women, aged 63 +/- 12 years). In order to obtain an accurate analysis of HRV changes, we only included ischemic episodes characterized by silent ST-segment elevation, lasting at least 3 min and without any ST change in the previous 30 min. HRV indexes in the time domain (RR interval, standard deviation of RR intervals [SD], pNN50, r-MSSD) and in the frequency domain (LF = 0.04-0.15 Hz, HF = 0.15-0.40 HZ, LF/HF ratio) were calculated on 2 min intervals, centered at 15 min before (15B), 5 min before ed 1 min before (1B) the appearance of ST elevation, as well as at peak of ST-segment elevation. Of 161 ischemic episodes found on 24-hour Holter recordings, 60 (37%) fulfilled the inclusion criteria for analysis (4.6 +/- 3.5 episodes/patient, range 1-12). The duration of the selected episodes was 6 +/- 2.5 min and ST elevation was 2.2 +/- 1.0 mm. Heart rate (HR) did not have any change before ST elevation, whereas it showed a small, but significant increase at peak ST (73 +/- 12 versus 67 +/- 11 b/min at 15B, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Neurovegetative changes before and during episodes of silent ischemia in variant angina]. 792 52